Current controller



Svwe'nto'c GILBERT 5. DEY

Dec. 21 1926.

G. S. DEY

CURRENT CONTROLLER Filed August 21 I Patented Dec. 21, 1926.

UNITED STATES PATENT OFFICE.

GILBERT S. DEY, OF MOUNT VERNON, KEV] YORK, ASSIGNOR TO GENERAL OPTICAL COMPANY, INC, A CQRPORATIGN OF NEW YORK.

CURRENT CONTROLLER.

Application filed August 2'1, 1924.

My invention has especial application to the control of currentto various ophthalinological instruments mounted on or connected in a common star-.dard or unit deriving current from a common source, although it will be manifest that it is susceptible of a much more general application. It has heretofore been the general practice to regulate the voltage for the various instruments in such a unit, such, for example, as current supplied to ophthalmoseopes, retinoscopes, transilluminators, and the like. by employing both a fixed and a variable resistance. Not only is this uneconomical, but it is also attended with the danger of burning out the lamps of such small instruments when the operator shifts from one instrument to another in making an optical examination The various instruments as a rule are connected in multiple across bus members, and it is necessary to employ a voltmeter connected across the busses upon the reading of which the operator is entirely dependent for guidance in regulating the voltage to these instruments. Safety demands that he should always. in shifting from one instrument to another, first turn the rheostat entirely 0E, and then gradually turn it on to the proper voltage for the new instrument, but this precaution is frequently inadvertently omitted, and oftentimes with disastrous results. Furthermore, the current requirements for the various lamps frequently differ with the result that a safe voltage for one lamp will be excessive for another lamp in the same class of instrument.

My current controller is designed to eliminate this danger and the necessity of such careful precautions. In accordance with my invention, I employ a transformer of the proper ratio to step the voltage supplied to the bus members down to one which will be safe for all of the instrument lamps and in connection therewith a rheostat is provided which will enable the operator to regulate the intensity of the illumination of the instrument lamps according to the condition of the patients vision. the whole being convcniently and compactly assembled in a small casing having a plug which is adapted to be screwed into any lamp socket, as well as binding posts for attachment of the leads into the instrument holder.

Serial No. 733.251.

able front cover 2 and has on each lateral side binding posts 3 and l, while to its top end is secured a screw plug 6 of standard construction and adapted to screw into a lamp socket. \Vithin the casing is securely supported a unitary structure consisting of a transformer 7 and a rheostat 8. For ophthalmological purposes, the transformer will be of the proper ratio to step the ordinary service voltage down to volts, for ex ample, which will be a safe voltage for the lamps of all small instruments. The transformer is of standard type, having a rectangular, laminated frame or core upon the central transverse member of which the coils are wound. The rheostat, which is also of standard construction, is secured by a screw 9 to the lower end of the laminated frame on the front face thereof. Two corner strips 10 and 11 within the upper end of the casing are provided with intermediate grooves or notches into which the upper end of the transformer frame enters, as shown in the drawings. This holds the upper end of the unitary controller elements steady, and the unitary structure is of such length that the rheostat rests upon the bottom of the casing when the upper end of the transformer frame is in the grooves of the corner strips. Front and rear securing members are provided for the lower end of the unitary structure. As shown, a stud 12 is secured, as by a screw, to the rear wall of the casing and extends inwardly of such length as to engage the lower end of the transformer frame when the frame is in upright position. A removable transverse front strip 13 is secured on the bottom of the casing in front of the bottom of the rheostat and thus serves to hold the parts in position after they have been inserted into the casing. The cover 2 is secured by screws to the corner strips 10 and 11 and to the bottom strip 13. r

The primary leads 1 1 and 15 of the transformer are secured to the terminals of the screw plug in the usual way. The secondary terminal 16 is secured to the binding post 3, while the secondary terminal 17 is connected to the binding post 18 of the rheostat which has electrical connection with the adjustable switch member 19 of the rheostat, as is Well understood with standard rheostat constructions. The resistance 20 of the rheostat has electrical connection with the binding post 21, which in turn is connected to the binding post 4 by wire The stem 23 of the rheostat protrudes through the front cover 2 and has on its outer end, external of the casing, a manipulative knob which carries an index finger 25 cooperative with the calibrationson the cover.

It will be understood that in assembling or disassembling the parts, the strip 13 will be removed, which is effected by taking out the screws which attach it to the bottom wall of the casing. The connected elements will then be inserted and the top of the transformer frame entered into the retaining grooves in the strips 10 and 11 and the bottom of the parts moved back until the transformer frame abuts against the stud 12. The strip 13 is then secured in place, thereby securely locking the elements in the casing and the electrical connections are made, after which the cover 2 and the knob 24- are applied. It is to be noted that the casing 1 constitutes a framework which ties together and integrates the cooperating elements of the complete current controller into a compact unitary co-organization which is a single small device complete in itself, easily moved about and convenient to use.

It is obvious that various modifications in the details and arrangen'ient of parts herein described and illustrated for the purpose of explaining the nature of the invention, may be made by those skilled in the artwithin the principle and scope of the invention, as expressed in the appended claim.

1 claim:

current controller, comprising a casing having a contact plug and two binding posts secured externally thereto and having transversely grooved corner strips in one end, a

transformer having one end of its laminated frame entered into said grooves, a rheostat secured to one face of the other end of the frame and proportioned to rest upon the other end of the casing, front and rear retaining members in the casing for the rheo- GILBERT S. 

